Abstract: The invention relates to a motor-driven control valve for a liquid, in which a control member (31) effects a rotatory and/or linear motion. In order to achieve an improved torsion moment and controllability, the motion of the control member is produced by means of an ultrasonic motor. In one embodiment, the rotating plate acting as a control member (31) forms directly a mobile part of the ultrasonic motor. An oscillating body (36) is in contact with this part, the oscillations of the body being produced by piezoelectric elements (37). The oscillating body (36) with the piezoelectric elements (37) can be annular, thus surrounding e.g. the material flowing in the pipe. Owing to the invention, a compact and simple solution is provided, and the actuating of the plate does not require as many transmission elements as when usual electric motors are being used.

Abstract: The invention relates to a single-grip valve having a valve body with water inlets and a water discharge outlet and ceramic discs fitted in the body, the mutual position of the discs determining the mixing ratio of cold and hot water. One ceramic disc is moved by a lever which is attached with bearings to a turning piece fitted to turn inside the body. In order to limit the turning movement of this turning piece and, together with it, that of the lever, one of the members, the turning part and the body part surrounding it, is equipped with axial protrusions spaced around it and the other has respectively at least one axial protrusion. However, the protrusions of the different members do not overlap each other in the radial direction, but between the said members there is fitted at least one detachable limiting piece which can engage between the protrusions of one member and radially overlaps the protrusions of the other member.